Quick answers
- Which hospitals does Ellen M. McMahon work at?
- Medicare's official clinician data lists Ellen M. McMahon at 1 hospital: Martha's Vineyard Hospital Inc. This is where the clinician works or has privileges; call the hospital to confirm.
- Where does Ellen M. McMahon see patients?
- Medicare's clinician data lists 1 practice location in Oak Bluffs, MA. Call before your visit to confirm the address.
- What is Ellen M. McMahon's specialty?
- Medicare lists Geriatric Medicine as the primary specialty, and also Family Practice.
- Does Ellen M. McMahon accept Medicare assignment?
- Yes. Medicare's clinician data says Ellen M. McMahon accepts Medicare assignment (the Medicare-approved amount as full payment for covered services), as of 2026-10-02. Ask the office to confirm before your visit.
- What is Ellen M. McMahon's NPI number?
- 1962468959. The NPI (National Provider Identifier) is the clinician's permanent federal ID; you can look it up in the official NPI Registry.
Hospitals where Ellen M. McMahon works
Medicare's Facility Affiliation Data lists Ellen M. McMahon at these hospitals (updated 2026-10-02). Each hospital page shows its address, phone, emergency services, Medicare rating and all its clinicians.
- Martha's Vineyard Hospital IncOak Bluffs, MA · Critical Access Hospital · CCN 221300
Practice locations
Addresses where Ellen M. McMahon is enrolled with Medicare (CMS data updated 2026-10-02).
- 1 Hospital RdOak Bluffs, MA 02557
Group practices
Medicare enrollment lists Ellen M. McMahon as a member of this group (CMS data updated 2026-10-02).
- Martha's Vineyard Hospital Inc155 clinicians in the group
Specialties
- Geriatric Medicineprimary
- Family Practicealso
Other geriatricians in Massachusetts
Clinicians with the same Medicare primary specialty in Massachusetts — not a recommendation.
Clinician information
| Credential | MD |
|---|---|
| Medical school | Warren Alpert Medical School Of Brown University |
| Graduation year | 1998 |
| Gender (as listed) | Female |
| Medicare assignment | Accepts (Medicare-approved amount as full payment) |
| NPI (National Provider Identifier) | 1962468959 |
| Corrections | Report an error or suggest an update → |
Most corrections must be made at the source: clinicians update their NPI Registry record (NPPES) and their Medicare enrollment (PECOS); this page follows the next data release.
Sources
- Facility Affiliation Data — Centers for Medicare & Medicaid Services (CMS), data updated 2026-10-02, retrieved 2026-10-29
- National Downloadable File (Doctors and Clinicians) — CMS, data updated 2026-10-02, retrieved 2026-10-29
- NPI Registry — U.S. Department of Health and Human Services (NPPES), the clinician’s official record
- Medicare Care Compare — official Medicare tool to look up clinicians